Bicycle Frame w/fuel tank 3.75l - Black Built-in 3.75L gas tank Designed for the 2-cycle engines with 40 to 50mm wide front mount stud spacing, and also accepts 4-cycle engines Frame made especially heavy duty for gas engine applications Available with 135mm rear frame width for either single speed or multi-speed bikes. 38mm diameter downtube 70 degrees angle V frame. No other bike frame in the world is especially made for motorization. Seat post angle allows for level carburetor.